Abstract:Study on population genetic diversity, population genetic structure and population differentiation has become the main part of population genetics and the important content of species diversity along with establishment and improvement of molecular biological technique, electrophoresis, isozyme staining, RFLP, and so on. Simultaneously, breeders have also paid more and more attention to these. So it becomes one of the most important realms. In this paper, the models and methods are briefly introduced and discussed.Some new explanations about the distributions of genetic variations in populations are given.